Preventing childhood obesity from pregnancy on

While applauding the First Lady’s efforts to combat childhood obesity through the Let’s Move initiative, researchers from the Department of Pediatrics at the University of California, San Francisco say that the campaign’s efforts focused primarily on behavioral and nutritional intervention—in school or at home—will yield “limited success.” In an editorial published online this week by the New England Journal of Medicine Drs. Janet M. Wojcicki and Melvin B. Heyman argue that any attempts to have a more substantive effect on childhood obesity must start well before children reach school age. “Indeed, prevention must start as early as possible, since school-aged children already have an unacceptably high prevalence of obesity and associated medical conditions,” they write. According to data from the Centers for Disease Control and Prevention, nearly one third of U.S. children are overweight.

Wojcicki and Heyman are among a growing number of obesity researchers and health professionals advocating for childhood obesity prevention beginning in infancy, pregnancy, and even earlier. In November of last year, the Institute of Medicine formed a new committee to specifically address obesity risk factors and intervention efforts for children under age 5. As Dr. John Harrington, an associate professor of pediatrics at Eastern Virginia Medical School and Children’s Hospital of The King’s Daughters, told TIME last month, “”You’ve got to look at it in terms of intervention and prevention,” Harrington says. “If you’re trying to intervene at age 5, you’ve already missed the boat.”

One issue that early intervention advocates stress is the need to improve education about pregnancy weight gain. A study highlighted by Wojcicki and Heyman finds that women who gained more than the amount of weight recommended by the IOM were 48% more likely to have a child who was overweight by age 7. A study published in the American Journal of Clinical Nutrition and highlighted by Reuters today, found that children whose mothers gained more than the amounts recommended by the IOM had 10% more body fat by age 6, on average, than those whose mothers gained weight within the recommended range. A small study from researchers at the University of Auckland recently found that women who did moderate exercise throughout pregnancy were more likely to give birth to lower weight babies (who were still in the healthy weight range), potentially reducing their later risk for childhood obesity.

Wokcicki and Heyman make the case that, while the Let’s Move campaign is a step in the right direction, in order to achieve more significant results, it is important to proactively incorporate pregnant women, infants and young children. “We believe that including prevention efforts for these groups will have the longest-term effect on the obesity epidemic in the United States,” they argue.